Lubricating system of internal-combustion engines



' 1927. l 624689 APnl 12" E. J. swEETLAND -1 i LUBRICATING SYSTEM OF INTERNAL COMBUSTIONEGINES Filed Nov. 19. 1920 2 sheets-sheet 1 u y 1,624,689 I APH] 12 1927 E. J. swr-:ETLAND LUBRICATING SYSTEM 0F INTERNAL COMBUSTION ENGINES Filed Nov. .19, 1920 2 sheets-sneetz 'mmmmu IIIMITU A TTORIVEYS ERNEST J. sWEETLAND, 'or MoNTcLAm, NEW JERSEY. i

LUnnIcArING srs'rEM `or INTERNAL-consommer ENGINES.

Application led November 19, 1920. Serial No. 425,042.

This invention relates to improvements in lubricating systems of internal combustion engines and is especially adapted for use in vinitial clear condition. of such deleterious matter is of the utmost connection with the internal combustion en gmes'iqffmotor vehlcles, such as automobiles,

.aeroplanes motor-boats and the like, and

has for its object to providefor the removal ofall of the foreign deleterious matter which maybe suspended in the oilwith, which the ,moving parts of the engine are lubricated, thereby insuring thatthe oil supplied to such parts will be freed lof all such deleterious matter and be substantially restored to its The removal of all importance in order t'o insure aga-inst undue wearY of the engine parts, as the presence of such matter in the pil will cause an inefficient operation of the-engine and will eventually wear the parts to such an extent as to render it necessary to repair or renew Vthe same. The impurities usiially found suspended in the' lubricating oil after the engine has'been operated for some time, are dust,'dirt, metallic particles and carbon.

According to present practice, the largerparticles are removed from the oil by passing t1ie"oil'tl1roii.gh wire screening, but such screeningiloesnct remove the fine particles as they pass readily through the' sci eening now commonly employed. It is, therefore,

only a mattei' of time before the crnk'case oil is contaminated to such an extent as to render it neressary to remove it and replace it. with a4 supply of clean oil. y

According to my invention, the crank caser oil is so thoroughly 'cleaned that it is practically restored to and maintained in its initial condition, .as a @Oneqtlcnce of which' it may he 'used over an'dfdver'jagain, and the' replacing thereof-by` a fresh supply of clean oil is rendered unnecessary. By avoiding ,the necessity of renewing the oil at frequent intervals, as is now the lcase, the expense in cident tothe operating of the engine 1s ma- Y terially decreased, 4and the dancer of any of the co-afsting moving parts of tie engine be-f ing damaged, due to foreign matter suspended in the oil, is removed. The restoring of the .oil to' and maintaining it in a clean fsate is effected by passing it through a filteradapted to 'remove all foreign matter from the oil and so arranged and connected that whatever may be the resistance of the. filterv circuit to the flow therethrough, the presence of the lfilter in the system will in no` way .interfere with the proper lubrication-of the co-acting moving parts of the engine in the usual manner. v

In the accompanying drawings forming part of th1s specification, wherein I have shown a'preferred embodiment of myinven-y tion, for the purpose of illustrating the principle thereof, i

Figure 1 is a side elevationvof an internal combustion engine embodying my invention,

parts being shown in section;

Figure 2 1s a deta1l view on an enlarged scale of a. portion of the vehicle instrumenthoard and the sight glasses'through the oil flows to and from the filter;

Figure 3 is a plan View of the filter; Figure 4 is a View thereof partly in side elevation and partly in section; f

Figurel 5`is a plan view of one ofthe filter elements, parts being broken away, and y Figure 6 is a detail :sectional view, on an enlarged scale, of a portion of the filter.

which Referring to the drawings, 1 represents an internal combustion engine of any suitable type having a crank case 2 which contains the oil for-lubricating the. co-acting moving` parts of the engine. Mounted upon the engine casing, or upon the frame of the vehicle, is a vpump 3 of any approved type, which may be the pump `usuall)7 employed in connection with forced feed lubricating systems. The pump 3 is provided with an intake ipe LI-eetending wit-hin the crank case2 and av 'ingfits open, inner end positioned adjacent the bottom of the erankcase, and an outflow pipe 5 which serves to conduct oil from the l pump to the bearings of the engine, or to any otherv parts thereof theI lubricationl of which is desired. This portion of the drawing is purely diagrammatic, the dotted c0nnections 5a representing the tubes which lea/d to bearingsv orother parts requiring forced feed lubrication, or they may represent ducts leading to a level pan. where splash lubrication is employed. vCommunicating with the pipe 5 is a pipe 6 leading to a filter 7, hereinafter described, from which the filtered oil is conducted through ipe 8 tothe' crank case 2. ',Interposedin tlJ sight glasses 9 and 1f) mounted in any suitable ma'nner upon the instrument board' 11 of the vehicle and visible to the driver through a window 12 lformed in the board 11, whereby he may observe the flowof oil to and from thel filter 'in order to ascertain if oil is flowing in a proper 'manner and if ends`of the sightI glasses in order to permit i of the Withdrawal of some of the unfiltered -Should the. pressure of or filtered oil for testing or other purposes, desired. A pressure gauge 15 mounted upon the instrument board 11, to indicate the pressure in the filtei` circuit, is connected by a pipe 16 to the pipe 6 through which pipe the oil is conducted to the filter 7.

Communicating with the pipe 6 at any desired point is a relief valve 17 of any suitable type provided with an outlet pipe 13 communicating with the crank case 2. As shown, the relief valve is provided with a valve member 19 in the form of a 'ball normally held upon its seat, to prevent oil from fiowing from the pipe 6 to the-pipe 18, by a spring 20, the tension of which may be varied by varying the position of the spring engagin vmember 21 adjustably mounted Within t ie easing of the relief valve 17. By

adjust-ing the 'member 2l within the valve casing the spring 20 which normally holds the ballvalve 19 upon its seat, is placed un der such tension as will insure that the oil flowing through the pipes 5 andvt will be under aworking pressure sufiieient to lubricate properly the engine parts and to overcome the back pressure offered to the flow of oil through lthe filter, as herinafter described.v the oil rise above this working pressure, diie to any clogging in the oil circulating system or to the fact that the pump delivers more oil than can fiow through the filter and circulating sys-em, the ball valve will be forced from its seat thus` pei'- niitting some of the oil to pass through the relief valve into the pipe 18 through which it is returned to the crank case. W'hen the pressure of the oil within the circulating system returns toits normal working value, the spring 20 forces the bal-l valve upon its seat, thus preventing any ot the oil being returned to the crank case through the valve, and pipe 18. lt will thus be seen that the reliefl valve serves to prevent the oil pressure from rising above. a predetermined value as l a. result of which there is no danger of its increasing to such an extent that the operation of the pump will be affected.

The filter 7. which may be of'any suitable construction, is shown for purposes of illustration as comprising a shell or body portion 22 having an open upper end closed by a cover 23 removably held in position by boltsA orfserews 24. The filter construction employed, however, must be efficient as a filter to,accomplish the purpose of thoroughly cleaning the oil as stated. The structure herein shown and described is a preferred form thereof, thoughv many inodifcationsin form and design are permissible. The cover is provided with lugs 2 5 adapted to receive bolts 26 serving to secure the cover to a sup- -teriorof the filter shell.

porting block 27 mounted upon the vehicle dash 28.' Carried by the cover l23, and preferably formed 4integral therewith, are inlet and outlet duets 30 and 31, res eetively, coinmunicating at theirinner en s with the'in.-

The outer ends of the -ducts 30 and 31 are seated within recesses in one side of the block 27 and coniinunicate with passages and 33 formedv therein and which, inftnrn, communicate with the pipes 6 and 8,7tlie ends of whichf are seated in corresponding recesses in the other side of the within the shell 22, with its upper end extending through an opening in the cover 23, is an ,axially positioned tubular niember'34 having a closed lower end and provided with an opening 35 in itswall adjacent its upper end communicating with the bore'ot the tubular member and reg.- istering with the'- inner `eind of the outlet duct 31 on'- the cover 23. The tubular member 34 is provided with ashoulder 36 engaging the inner surface of the 'cover-23 and with a ,nut 37 threaded upon the threaded upper end ot' the tubular .member and engaging the upper surface of the-cover.

block 27. Positioned Mounted upon the tubular member 34 are a plurality ofannular filter elements spaced from one another by annular spacing meinbers 38, formed of any suitable materiah the filter elements and spacing members being removably maintained in assembled position upon the tubular member by a nut 39v threaded upon the lower end thereofj Each filterelement consists of an annular 'meinber40, formed of' coarse wire screening. reticulated metal, or other suitable material.

enclosed within a easing or envelope 41' formed-of asuitable filtering material, the member 40 servingto hold tl'ieshcets of filter cloth or other filtering material spaced from one another. tol form drainage areas communicating with perforations Lf2 formed in the wail of theftubula-r i'iieii'iber and comy,llt

iniiuicating with the bore thereof'.4 'lhefilter elements. as shown in Fig. 4. do not.

'abut or fit close against the walls of the shell 22, but leave a narrow clearance between their pcripheries and said wallsI to provide a fiow passage for the incoming oil.v f

along the walls of the shell throughout. itt length.- rlhis flow passage is in communication with the numerous spaces between the filter elements, which together provide-niiimei-ousl restricted fiow passages for the oil to the filter a'reas. the filter is such as to provide a very large filtering area and a maximum. ot' fil-tering ef'- ficiency in a minimum lspace-a compactness of filter structure that has great advantage. in anaiitomotive filtering system. i

',lhe casings or envelopes 4l are formed of a material of such fine texture that any fine particles of foreign matter, such as carbon,

'l`lius.tbe structure of f "usamos which may bev suspendedv in the oil, cannot' pass therethrough but will be `depos1ted upon the surfaces thereof inthe form'y of a "slime bed. Furthermore, the material of which the casings are formed must be o f such fine texture as to offer an appreciable resistance to the passage of the oil therethrough, thus requiring the oil to be supplied to the filter der pressure sufiicient to overcome the back pressure due to the resistance offered to the passage of -oil by the trasing's. The casing's or filter cloths should be of such fine texture that they .will.@permit the 4passage therethrough of not more than one gallon of clear oil per square foot of filter are'al per hour when the oil is under a pressure of one Y pound per square meh under normal .workingconditions. In fact the resistance is Vusually so great that the rate of flow is often below one quart per square ,foot of filter area per hour even at ten or fifteen pounds presi sure per square inch.` Owing tothe fact that the casings a're formed of a material having an extremely fine texture the foreign matter deposited upon the surface thereof during the filtering operation will be deposited over the entire surfaces of the casings in layers of substantially uniform thickness throughout. Although the passage'of the filtered o il through the casing of each filter elementos retarded by reason ofthe fine texture thereof and by the slime bed formed on the surface thereof, the required flow of' filtered oil through the filter isl obtained vbyv reason of the extensive filter area provided. by the com- -bined filtering elements, and by oil to be filtered is under pressure. .The filter area shouldbe not less than the total piston area of the engine, an'dlfor the best yresults I employ six totenl square feet of fil-ter surface vfor the average automobile. The easings 41.01 the filter elements are preferably thereof or applied to the 'a fine mesh,

formed of a close Woven cloth fabric such as duck. canvas, chain cloth orthe like, or they may be formed of wire screening having or they mayl be made of felt or lasbestos cloth. Y may be'formed' of wire screening of a comv paratively coarse mesh having fibrous ai,-

bestos. or the like. woven through the meshes screening in such aina-nner as to form, in effect. a sort (if-felt surface which is of such Gir/Will prevent the passage therethrough of carbon particles and the like. I may even employ' filter elements of porous stone or earthenwure or unglazed porcelain (such as is used in a Pasteur filter) without departing from the .spirit of my invention.

It will, offcoursc. be understood that invention is not limited to casings formed of the filtering material specified. nor to the particular construction of thefilter elemcn's shown and described, it being merely neces- --through l manner.

surfaces of the several filter? reason of the fact that the movement, ofthe mechanical engine tl ough the mixture of If desired, the casings Witlnn e crank fine texture that itthe.

sary' OPvide' an OXteI-lsive'fl'ter'area of such Afine texture as to offer .appreciable resistanceto the passage of clear oil therethrough' and to prevent the passage :of the finest particles o. matter that may be suspended in the' be filtered.

Although the density of theflter elements permits only ,slow seepagetherethrough ot' -Y zolids, their ar-" carboni or other foreigr oil to]K ported Within an annular casing 43secured-.

to' the dash 28 of the vehicleor any other suitable part thereof and provided with a chamberv 44 having an inlet nected to the exhaust manifold of the enf gine', and an outlet with the atmosphere. In operation, a portion of the hot exhaust gases frolntllerenl gine will pass through the chamber gases exhaust into the outlet pipe 46.

the pipe 45 into and 44, from which the the atmosphere through The'flow of the hot exhaust gases through the chamber 44 Serves' to heat the oil within the filter, thereby preventing it from becoming' so viscous j and sluggish in cold Weather tha'it cannot pass through the filtering surface in un -efHcient The flow of the gases to the chum# ber 14 may be controlled by a suitable-valve 47 positioned within the pipe 45 and operatively connected to the 'end of an actuating rod 48, `the otherend ofl which may extend through the 'infytrument board l1 and bc provided with a suitable handle to pern'iit the rodto be actuated by the driver to open and c1059. the valve'. f Y

During the running of the engine .it frequenti happensthat Water finds its way into t e crank case owing to condensation orv other causes, and thisv wat-er may' become emulsified with the oil, due to the rapid parts of the oil and water .the lubricating qualities of the oil are greatly reduced. lIf no impurities .are su'pended within the oil the Water will separate from the oil after the mixture has been allowed to stand for some time, butl if any impurities are held in suspension water remains emulsified With the oil for a much longerU period of time, and there is practically no tendency for the water to separate from the oil. that when the flime bed is formed upon the filtering medium of fine texture, as above described. the ready passagey therethrough of Water which may be mixed with the oil is be separated yfrom, the. oil and, will 'remain pipe 45l con- I Within the oil, the,

I have found byL tests .so pipe 46 communicatingv case, as a result ofl which 'IH withinthe filter shell. The thus separated Water will collect within the space at the 'l bottom of the s c u v impurities -tion,`whilev the remaining portion or ltubular member 34 into vwhereupon it fioWs v 3l to the pipe filterfshell, which serves as a collecting chamber, and may be w'ithdranvnv therefrom by a suitable drain-cock 49. As the filter medium also Serves to remove all of the suspended impurities from the oil, thereby keeping the oil clean, there is less likelihiaod vof the water emulsifying with the' oil than is the case when the oil contains in suspension.

normal conditions operation of the engine, the pump 3 will withdraw oil from the crank case- 2 and force it'tovflow continuously through the oil circulating system, a portion of the withdrawn oil being forced through the pipe 5 to the parts of the engine requiring lubricaa part of it is forced through the pipe (i to and through the inlet duct 30 into the filter shell. After entering the filter' shell th'e'clear oil is forced through the filter area formed by the casings 41 of the yseveral filter elements into the drainage areas thereof from which it 'passes through the perforations 42 in the the bore thereof. T he filtered oil is forced upwardly through the bore of thev tubular member until it reaches'the opening 35 in the wall thereof through the outlet duct 8 which conducts it back to y,Under .i during the the crank case 'upon 'the oil to insure an efficient operation of the` system is maintained by the relief valves l71as above explained. After a layer of slime has been collected upon the filtering medium, the. back pressure, ofthe filter of its resistance to the flow of oil is effective "to limit the flow of oil through the filtering circuit, so that 'sufficient oil for proper lubrication is continuously supplied to the work-l ing parts of the engine. Should the filter become clogged from unduly long use to. such an extent as to prevent it from functioningin a proper manner, the increase in theback pressure merely results in an'increase in the amount of oil which returns to the crank case Athrough .the relief valve and noharm results. Therefore, the operation of the pu1np willnot be affected by any increase in theresistance loffercd'to the flow of oil through the filter` and consequently there can lic-nointerruption to the flow of oil through the pipe, 5 to the parts of the engine requiring lubrication. By observing the flow of oil through the sight glasses 9 and 10, the driver can ascertain at a glance -if the oil is circulating properly, and hy' observing the difference in color between the oil flowing through the sight glass 9 into the Y filterand the oil glass 10 after having passed through the filter, the driver can tell if the filter is functioningv properly. When the filter unit is prevented, would result 'supply-of oil to the bearings for proper 2. The necessary pressure` flowing through the sightv inattesa new and until a4 bed of slime has been deposited thereon, its resistance to the flow of oil may be insufficient to ensure a proper' supply of oil to the parts to be lubricated. A valve 50 or other appropriate means for resisting or controlling the flow of oil in the filter circuit is located in one of the conduits of the filter circuit, as for example, in pipe 8, so that when the filter is of low resistance, the resistance ofthe filtering circuit may be' made enough to` ensure sufficient flow of oil in the lubricating circuit for proper lubrication ofA the enginevparts. Also. should the filter become ruptured during use, the resistance' in the filter circuit may bev regulated by the valve 50 to prevent a free. flow of oil through the filtering circuit, which, if not so in an insufficient lubrication. s Any fine carbon particles or other foreign matter will be deposited upon the filter surfaces of the several filter elements in an even layer, as above set forth, to form a slime bed which assists in the filtering action; At the start, some of the finest particles may pass through the filtering material but the larger particles cannot pass therethrough, andthese together with other impurities, will in a short time form or build up a slime bed which lwill effectually `prevent the passage of even the finest particles.

`As the flow of oil through the filter is con-A tinuous during the ruiming of the engine'7 the` oil will, within a short time, be freed 100 from foreign matter which may be suspended therein. and any foreign matter that may become mixed with the oil during the operation of the engine will also gradually be rei'noved. lt will thus be seen that the oil within'the crank case will he maintained in practically a clear state,l freed from impurities and foreign matter. and may be used over and over again and need not be withdrawn and replaced by a. new supply of oil. lt has been found in practice that an engine embodying myv invention may be operate for months andthat the vehicle may be run for thousands of miles without draining the crank case to get rid of accu! iulated impurities. and that at the end of tiiat time the oil in the cranit case will be almost', if not perfectly, clear. lt is merely necessary to add oil from time to time to compensate for any loss of oil due to wear, evaporation, leakage or the like. y

It should be understood that in this system of employing a pressure filter of exceedingly fine texture l obtaina clea'r bright filtrate resembling new oil. and although the rate of flow through the filter is exceedingly slow, the purifying process is going on steadilv while the engine running` and in efthe same as withdrawing several quarts of the crank per hour; and -re same at an e lualate with alike v unie ofzperfectl cear o il. y l l While I have illustratedand described my invention in connection witha preferred 'en {bodiment thereof, it will be understood that fia AI do not intend to limit myself to the specific embodiment -shown, but that Il intend to] coverl my f invention broadly in whatever form its principles may be ein loyed. Obvioyed may be ously the type of filter em greatly diversified without the spirit of theinvention.

eparting from Having thus described-my invention','1`

' v ing oil therefrom and delivering a portion of thex oil directly to the engine and another portion of the oil to a purifying device from which the oil freed from deleterious matter,l

' is returned-to said crank case.

withdrawing oil from sai 2. The combination of an automobile internal combustionengine having. a crank case, a filter, and single ump means for d)'crank caseand delivering a portion of the Withdrawn oil to said filter and another portion of the oil to the engine, and means whereby the oil passing through said filter is returned to the crank case.

3.The combination of an internal combustion engine having a crank case, a filter' having its youtlet communicating with said crank case, and means for withdrawing oil from said crank case and delivering a por- `tion of thewithdrawn oil to said filter and another portion of the' oil .to the engine parts.

4. The combination of an internal combustion engine having a crank case, a filter adapted to offer resista-nce to the fiow of oil therethrou h and having its outlet communicating with said crank case, and means for withdrawing oil from said crank case and delivering a portion of the withdrawn oil to said .filter and another portion of the oil to the engine parts.

5. The combination of, an`r internal combustion engine having a crank case, a filter adaptedto offer resistance to the flow of-oil ,therethrough and -having its" outlet communicating'with said crank-case, a pump oil from said crank case,

fromsaid pump in part to said filter and in part to the engine parts.

6. The combination of an internal coinbustion en ine having a'crank case, a pressure filter' aving its outlet communicating with said crank case, a pump for withdrawingl oil from Said crank case, and means for de 'vering a portion/of rthe withdrawn oil to sure filter having its outlet closed luy-pass operatively filter andanother portion of the to the engine parts. v

Q7. T ve combination of an internal combustion engine having a. crank case, a pres- 'sure filter having its outlet communicating the t-hus deliveredV oil at a pressure above predetermined value at normal engine speeds.

9. The combination of an internal combustion engine having la crank case, a prescommunicating with said'crank case, means for withdrawing oil from said crank case and delivering it under pressure in part to said filter and in part to the engineparts, said means being constructed and arranged to maintain the thus .delivered oil at a pressure above predetermined value'at normal engine speeds and means operative to prevent such pressure from exceeding a predetermined value.l

bustiou. engine having a crank case, a pressure filter having its outlet communicating with said crank case, ing oil from said crank case and delivering it under pressure in part to said filter and in part to the engine parts, a normally associated with said first-named means andc'oinmunicating with said crank case, and means adapted to open said by-pass when the pressure of the delivered oil exceeds a predetermined value.

11. The combination of an internal combustion engine having a 'crank case, a pres-4 sure 'filter having its outlet communicating with said crank case, a ypump for withdrawsaid second -mentioned pipe andadapted to be' opened when the pressure within said pipe exceeds apredetermined value, anda pipe leading from said valve to said crank 685B.

means for withdra-W- ing oil from said crank case, a pipe leading iis lao

las

595 10. The combination of an internal com- 13. The combination of an internal combustion engine having a crank case and a forced-feed lubricating system, a pressure ,filter adapted to receive oil under pressure iis' from said system and having its outlet communicating with said crank case, andmeans for'v` supplying oil to` the filter, said means maintaininga constant flow of oil through said lubricating system irrespectivevof the passage vof oil to said filter.

14. The combination of an internal combustion engine having a crank oase and a forced-feed lubricating system including a ump, a filter circuit including a pressure lter adapted to receive oil under pressure from said pump, said filter being capable of simultaneously removing from the oil suspended impurities and water that may be mixed therewith,'and means in said filter circuit for observing the condition of the of filtered and unfiltered oil may 15. The combination of an internal combustion engine having a crank case and a forced-feed lubricating system including a pump, a pressure filter adapted to receive oil Linder pressure from said pum said filter being capable of simultaneous y removing, from the oil suspended impurities and water that may be mixed therewith, and means for fied oil as1 it flows from drawn.

17. The combination of an internal coinbustion engine having a crank case, a pressure filter, means'for withdrawing oil from said crank case and delivering it under pressure in part to said filter andin part to the engine parts, and means associated-with the filter forheating the' oil before its passage thru the filtering medium.

18. The combination `of an internal coinbustion engine having a crank case, a filter. capable of simultaneously removing from oil 4suspended impurities and water, and one pump means for withdrawing impure and water-contaminated oil from said crank case and 'delivering a portion of the Withdrawn mixture to said filter and another portion of the mixture to the engine. 19. The combination of an internal combustion engine having a crank case, a filter capable of separating water from oil having its outlet communicating with said crank 'case and one uni means for withdrawing 3 h oil from said crank case and delivering it to said filter, said filter being provided with a collecting chamber to receive water sepaf vtending to said filter,

neaacsaf V'rating from the oil passing through said filter. L

20. Ina purifying system for lubricating oil of'intern'al combustion-engines, a pump, a filter, a main oil reservoir, a suction pipe for thepump extending into said main oil reservoir,'a discharge pipe for the pump extending to said filter, a pipe connecting to said discharge pipe and leading to the parts ofthe engine to be lubricated, a pressure controlled valve connecte-d and arranged to relieve the pumpv from excessive back pres` sure from the filter, and a discharge pipe leading from the filter to the main oil reservoir.

21. In a purifying system for lubricatingI oil of internalcombustion engines, a pump,

a filter, a main oil reservoir, a suction pipe l for the pump extending into said main oil reservoir, a discharge pipe for the pump exa pipe connecting to said discharge pipe and leading to the parts of the engine to be lubricated, a pressure controlled valve connected and arranged to relieve the pump from excessive back pressuie from the filter, a discharge pipe leading from the filtei to, the main oil reservoir,A and means to regulate the flow of oil through the filter. l

22. In combination with 'an internal coinbustioii yengine having parts to be lubricated, an oil pump, a'device vfor separatingan impurity from the oil, and means normally operative to convey part of the oil 'delivered by'said pump to the separating device and another partto the parts to be lubricated, whereby said parts and sai-d device are 1each supplied with oil independently of the other at all engine speeds.

, 23. The combination of an internal conibu'stion engine having a crank case and a forced feed lubricating system including a pump, a pressure' filter adapted to receive-oil under pressure from said pump, said filter being capable of simultaneously removing from the oil suspended impurities and water that may be mixed therewith.

24. 'The combination with an internal combustion engine of a lubricating systemvin cluding an' oil reservoir, a pressure filter communicating with the reservoir, single means for forcing 'oil from the reservoir through the filter and for supplying the normal amount of oil to the working part-s of the engine atl all times without passing through said filter.

25. The combination with an internal com bustion engine of a lubricating system including an oil reservoir, a pressure filter communicating with the reservoir, single means for forcing oil from the reservoir through the filter and for supplying the normal amount of oil to the Working parts of the engine at all times without passing.

iis

for relieving excess pressure in said system.

26. The'combination with an internal combustion engine of a lubricating systemincluding an oil reservoir, a pressure filter communicating with the. reservoir, means tol 'regulate 'the fiow of oil throughthe filter,

single means for forcing oil from the reservoir through the filter, said reservoir havv.ing provision forv supplying oil therefrom to the engine Without passing through the filter, and -a' pressure relief valve for relieving excess pressure in said system.

27. The combination with an internal combustion engine of a lubricating system in cluding an oil reservoir, a pressure filter communicating with the reservoir, saidfilter having filter surfaces of dense material arranged in compact form and liavingan aggregate filter area notably in vexcess ofthe iiston area of the engine, and single means im' forcing oil from the reservoir through the filter, and forl supplying the normal amount of oil to the working parts of the engine. at

'all times'witliout passing through said filter.

y28. In combination with an internal coml bastion engine, an oil reservoir, a lubricating circuit, a filter circuit, pump means for forcing oil from said reservoir through said lubricating circuit,a filter, conduits leading from said pump means. to said filter and a from saidvfilter to said reservoir, one of said' conduits having provision for presenting such resistance to the flow. of oil therethrough vthat the desired lflow of oil through saidA lubricating circuit is continuously maintained,y

29. In combination with 'an internal combustioii engine, an oil reservoir, a lubricating circuit, a filter circuit', pump means for fore# ing oil from said reservoir through said `lubricating circuit, a filter, conduits leading from said pump means to said filter and from said filter to said reservoir, one of said conduits having a valve for presenting such resistance to thejlowof oil therethrough vthat the desired flow of oil through said lubricating circuit is continuouslymaintained. v30. YIn combination with an internal combustion engine, an oil reservoir, a lubricating circuit, pump means for forcing oil from said reservoir through said lubricating circuit', and a branch circuit including a filter receiving oil from said pump means, said filter, containing a dense filter surface soarranged as to permit only slow seepagetherethrough of oil freed from deleterious solids and being ofsufiicient area to permit in the vaggregate a rate of filtration equal to the normal rate of contamination of the oil underoperating conditions, the normal back pressure of said filter tending to resist fiow of oi] therethrough andv to prevent 'diversion' through said filtering circuit of oil required in said lubricating circuit for proper` lubrication of the Working parts of the engine.,

31. In combination withan internal combustion engine, an oil reservoir, a lubricating circuit, pump means for forcing oil from said rgservoir through said lubricating circuit, a branch circuit including a -filter re-A ceiving oil from said pump means, said'filter containing a denseifilter surface permitting only slow seepage of .oil freed from deleterilous-'solids and being of sufiicient area to permit in the aggregate a rate of filtration equal to the normal rate of' contamination of ther ERNEST J, SWEETLAND. 

